Process of die-cutting wood and similar materials.



E. B. L A. B. WILDER. PROCESS 0F DIE CUTTING WOOD AND SIMILAR MATERIALS.

APPLICATION rILBDNov.9,1912.

1 ,082,985.' Patented Dec. 30, 1913.

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L y mi; /r y E. B. L A. B. WILDER. PROCESS OF DIE CUTTING WOOD AND SIMILAR MATERIALS.

APPLICATION FILED NOV. 9, 1912. 1,082,985. Patented Dee. 3o, 1913.

2 SHEETS-SHEET 2.

M myf- 'UNITED STATES PATENT oFFroE.

EDWARD B. WILDER AND ALLEN B. WILDER, 0F ST. LOUIS, MISSOURI.

PROCESS OF DIE-CUTTING WOOD AND SIMILAR MATERIALS;

. Specification of Letters Patent.

Patented Dee. 30, 1913.

Application led November 9, 1912. Serial No. 730,339.

To all 11:71am it may concern."

Be it known that we, EDWARD B. VILDER and ALLEN B. WiLnER, citizens of the' United States, and residents of the city of St. Louis and State of Missouri, have invented a new and usefullrocess of Die! Cuttingrood and Similar Materials, of which' the following is a specification.

This invention relates to processes of die-cutting sheets of wood and other matevrials, such as cardboard, pressed ber, leather, rubber and the like, and is particularly adapted to cutting intricate patterns, and for inlay Work.

It has forits principal objects to avoid injuring the surface of the material; to prevent splitting and' splintering or crushing the material; to enable thick material to'be cut with la thin blade; to shear the material into -sections havingr clean cut rectangular edges; to obviate the necessity for preliminarily treating the material ;v and to attain certain other advantages which will hereinafter more fully appear.V

Attempts to cut out woodenipieces having intricate outlines by ordinary die-cutting orpnnching methods have resulted in splitting and splintering the wood, and in some, cases the surface of the wood has been injured. Other disadvantages and difiiculties have arisen in such methods of die-cutting rubber, cardboard, pressed fiber, leather-and the like. For instance, the edges of the cut pieces are not clean cut and true, and if a thin cutting blade is used it buckles andj twists and also sticks to the material. Heretofore it has not beenpossible to cut com: posite patterns by means of dies except when the material`is 'very thin.

The present invention consists principally in clamping the material to be cut by means of a pressure distributed in such a way as to insure and maintain prbper alinement of the cutting knives r blades with respect thereto throughout the cutting operation'. It also consists in supporting the cutting blades by means of resilient pads on both s'ides thereof, whereby thin blades may be used'ior cutting thick material, sai d pads likewisebeingadapted to firmly clamp the material. before the knife edges reach the cutting position.

'In the accompanying drawing which-I orms part of this specification and wherein like symbols refer to like parts wherever they occur,-Figure l is a vertical section of a die mechanism suitable Jfor carrying out the process, together with portions ofcertain part-s of, an ordinary press on which said die mechanism is mounted; Fig. 2 is a horizontal section on the 1ine12-2 of Fig. l; Fig. 3 is a fragmentary View, on an enlarged scale, showing the parts in normal positions; Fig. 4 is a similar view showing the positions of the partsas the cuttingY blade is about to enter the work; Fig. 5 is a similar view after the cutting blade has passed all the way through the work; and Fig. 6 is a plan view of the cut out piece.

The process is conveniently performed by Imeans of suitable dies in an ordinary'prcss arranged as is shownqin the drawings. Above the bed'l, the press has a movable head or plate 2 which is'mounted on a ver-A tical reciprocatory plunger 3. The'. plunger may be operated by any suitable 4toggle or other obvious power mechanism' (not shown) according to the type of press that is used.

Secured to the under side ofthe head 2 of the press. as by screws 4, is a chase or rectangular frame 5 adapted to'reeeive and hold the die to be presently described. This frame or holder is provided with dowel pins which enter holes provided therefor in the head :2 so as to position said'holde'r properly to receive the securing screws 4. The holder s alsoV provided willi follower bars 'T which have the .inner ends of screws S swiveled thereto so as to clamp the die in place..

The die comprises a block or liz-.cking t) which may be of metal or wond, as desired. lf the die block is made of wood. a'continuous cut is made theren with a bandsaw or scroll saw, said cut being of the same con` tour as the article to be formed. thin cutting blade or knife 10 is fitted around the cut and the cut out piece is placed back in the opening within the'hlznle. 'lf-he blade may be lacked at intervals to the block. but lthis is not absolutely necessary :is-'the blade fmay be made to bear against the under side of the head 2: the tacks being used 'merely torhold 'the blade frompulling out of the .-block 9 while vthe cut material is-"being stripped therefrom and also to hold the vblade. in place on the bloek'wlien the latten is detached from the chase or holder The cutting blade or knite l() "may be made to conform to any .desirable contour,

t i i as for' example, the outline of a toy figure or image: or, as shown in the drawing, a

ack section for a toy chair. The arrange ment shown in the drawing illustrates that a plurality of cutting bladesA may be ar-Q ranged the one within the other, whereby the outer one is adapted to cut the Voutline or outer margin of t-he article and the other .is adapted to cut openings in said article simultaneously. A

The die block 9 is preferably made' out of a single piece, the cutout portion thereof being replaced .and mounted in -its original position; or `it may be divided into sections,

as indicated by the lines of division 11 shown in the drawing, and held together by the clamping elements 7, 8.

` Glued or otherwise secured to the under side 'of'tlie die lblock 9 is a body or layer of resilient material, preferably sponge rubber- "orlthe likehaving .a multiplicity of air or gas-filled pocketsor cells so that it may be 1 -v compressed-without any appreciable lateral elongation or spreading when confined b'etiieen walls. The surface area ofthe -layer of material 12may be such that its marginal portions underlie the chase or holder 5. -`In some eases, the under side of the die block i normal ,thickness of the layer of sponge .principally by the surface area of the object to be cut out and also by the surface a'rea of the material from which the object is cut, as will hereinafter more fully appear. The

rubber 12 depends principally upon the thickness of the material from which the objectis tobe cut. In practice it has been found expedient to have the body of sponge rubber of a thickness approximately three times that of a wooden board or sheet to be cut. For example, if the wood is one quarter of an inch thick, the sponge rubber shouldbe about three-quarters of an inch thick.d

lVhen the piece to be cut out has a surface area of more'than tive inches by five inches.

the size of the piece isl of but little conse-v quence as far asthe pressure per square inch is concerned. Therefore, for the relative thickness above stated, the sponge rub compressjto within less than tive-sixteenths of its normal thickness, and a safe maximum compressioufhas been found to beto not less than three-eighths. while the average compression is one-half. To keep the woodfrom splitting it is desirable that there should thick. the rubber should be. compressed about .-ne-eightli of an inch before the blade begiiis to enter the wood. Therefore, in such cases,.tlleedge ofthe blade should be normally one-eighth of an iiich inward from thc bottom face of the layerof sponge rub- Ofcourse, this is only typical with reference to spongerubber,.and where other similar substances are substituted the proportions may bevaried;` andthe variations in the relative proportions will depend somewhat oii the material to be cut. i.

To preserve the surface finish of the material to be cut and to build up the pressure on intricate cuttings where there is a tendency for the material. to bind on the blade ufhenstripping,4 it is 'preferable iii' some cases, to provide Va Vlayer- .13 of-.some relatively hard a'nd inelastic substance,'such as hard rubber,'c`ellulo id vor pressed fiber, on

, the under side ofthe layer 12-of the sponge rubber. In other cases, a thin; layer 14 of heet rubber maybe placedV on said layer 13. il

`he hard layer 13 servesas a binder for the underside of the layervv '12.," and fthe outer` of and also serves toiri'ctioiially hold the material being cutand thereby prevents 4.shifting while the cutting blade is.entering the material. Then these two .layers 13, 14,

are provided, the edge .of thelblade10 will be located approximately. Aone-,eighth .ofan

inch inward from the bottom .face of the outer layer, so-tliatz the sponge rubber layer l will have'the initial compression ofvon`ceighth of an inch, as abovesetforth. The sponge rubber not only serves to exert a pressure or clamping'actio'n on' the material being cut, but also supports the'blade laterally. Hence a relatively deepor wide and very thin blade may be used. The sponge rubber further acts as a stripper to remove the material from the -blade after the cut has been made. -z

It is desirable to create an equal support' on both sides. ofthe cutting bladeso ,as to prevent it from buckling and twisting. This is accomplished satisfactorily. when the blade is located so that there is a substantially equal mass of the sponge rubber on either side thereof; but should the blade be located near to t-h'e.. margin of the body of sponge rubber or close to the side of the chase or holder, it will then be necessary to havejthe body of sponge rubber extend under the chase, in which case the chase ought to be -deeper than the thickness of the dieblock and the' rubber cut away or rabbeted so-that normally the entire under vface of the body of rubber is in the same plane. In this way, the reduced thickness ofrubber Aunder the chase is. compressed to 'a "reater density than the balance. Hence, the lateral support for the blade is equalon both llt sides. The quantity of the rubber removed is determined by the degree of compression to be` given the main body of rubber, and, ofcourse, the relative thickness of the dieblock and depth of the chase or holder must correspond accordingly. So, too, in an intricate cutting Whereportions of the cut out piece are relatively narrow and necessitate locating two or more blades or rebent sides of a continuous blade close together, or where the different portions of the cut out object are of various proportions, a portion of the body of sponge rubber between the blades may be removed and a filler block or blocks of corresponding -proportions placed on the under side of the die-block, so as to secure an equalized lateral support for the blades and also to insure the stripping of the cut out piece from between the blades.

A platen or backing 15 of hard rubber, celluloid, pressed fiber, or an equivalent substance that will not dull the cutting edge of the blade, is mountedon the bed 1 of the press to support the board or sheet of material 16 which is to be cut; and in some cases, the outline of the object to be cut out may be cut or grooved in the platen or backing 15 so as to make a clearance for the cutting edge of the blade.

Certain Woods spread laterally under compression more than others and some have a certain resiliency which makes them have a greater binding'etfect on the cutting blade as it backs out of the Work. However, this binding does not depend entirely upon the friction of the Wood, but it is to be noted that the greater the cutting friction the more the wood binds. Therefore, it is obvious that Well seasoned close grained Wood is best adapted for treatment by the present process.

Toy get the best-'results the blade should have a long tapering cutting edge, and it should not. pass into the wood beyond the termination of its bevel, for the 'reason that the wood Wedges so tight that the blade would stick. So, too, clean cut edges are obtained by moving the blade relatively fast through the Work; and in some cases the cutting edge of the blade may be scalloped, serrated, or otherwise irregularly shaped, as desirable. By using the thin blades which the construction and arrangement of the device permit, pieces may be cut out for inlay work so, as to fit with exact nicety. That is, a piece may be cut out of a board or sheet of material and a like piece cut out of another board or sheet with the same die, and the respective pieces will fit the opening in either of the boards or sheets.

While the die shown and described herein comprises a form block on which the cutting blade is secured, together with the compression body of resilient substance, in

some cases the blade may be mounted on a separate carrier above the form block and reciprocated through the form block and body of resilient substance thereon. In such a case, suitable means may be provided to move the form block first so as to compress the resilient substance on the work, and then actuate the cutting blade. Also, in such a case, the blade may work through a snug litting sheath or tube which is ein pressible materials, particularly such as arev more or less cellular, may be used to advantage in lieu thereof, in carrying out the process of the present invention.

In practising the present process, the sheet of material to be cut is placed on a suitable backing or support and, while the material is thus supported, the cutting device is forced against it. In the forward movement of the cutting device, the sponge rubber first comes in contact with the niaterial and, by the time the cutting edge of the knife reaches the material, the pressure on the material transmitted through the sponge rubberI firmly clamps the material in place. If the material is easily compressible it will be compressed to the point where it may be cut with true edges before the knife touches it. The further forward movement of the cutting device causes the knife to enter and sever the material, while t-he pressure ou the material prevents the splitting or spreading of such material. During this action, the sponge rubber presses against both sides of the knife or blade and gives lateral support thereto,

thereby insuring the proper position and alinement of the blade. As the cutting device moves backward, the blade is withdrawn from the material while the latter is still under the pressure of the sponge rubber. The severed material is thereby stripped from the blade; and as the sponge rubber holds the material to the backing or support, the material is preventedv from splitting While the cutting blade is being withdrawn therefrom.

lVhat we claim is:

1. The process of die-cutting thick sheets which consists in subjecting the material to be cut to initial pressure throughout its engaged area and forcing the die blades into the material While laterally supportingl said blades throughout their length.

2. In die-Cutting thick sheets with knife blades, supportingl the blades laterally to L maintain them in normal alinement by applying pressure to both sides thereof throughout their length by the compression of a resilient pneumatic medium.

3. The process of die-cutting thick sheets in composite patterns which consists in forcing thin cutting blades arranged in pat-- tern form through the sheet While applying pneumatic pressure to the sides of said eutting blades.

il. In die-cutting compressible sheet ma terial by means of knife blades arraiiged in pattern form5 compressing the material and maintaining said blades in normal alinement by supporting them laterally through the application ol' a resilient eompressible medium applied to said material throughout its entire extent.

The process of die-Cutting thin Wood and the like, which consists in mounting the cutting blade snugly between sections ol a resilient comln'essible material with its cutting edge sunk within the face of such material, and then forcing said resilient eoinpressible material and blade against the Wood to be out, 'whereby the pressure due to change in volume of said compressible material compacts the Wood and supports the blade laterally While the blade cuts the Wood.

Signed at St. Louis, Missouri, this 1st day of November, 1912.

EDWARD B. VVILDER. y ALLEN B. VVILDER.

lVitnesses 1 (l. A. IENNINGToN, PALINE ANEBERG.

Coplas of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

